3,4,5 or even 6 outboards on fancy fishing boats?

Discussion in 'Powerboats' started by Squidly-Diddly, Mar 21, 2020.

  1. Rumars
    Joined: Mar 2013
    Posts: 643
    Likes: 242, Points: 43, Legacy Rep: 39
    Location: Germany

    Rumars Senior Member

    While the comments are funny the issue is actually simple. There are no current production high continuous horsepower gasoline engines made. If one needs a ~1500HP (continuous duty not dragster stuff) gasoline engine there is no new Packard 5M-2500, Allison V-1710, RR Merlin or DB 605 on sale at the local dealer. If anybody makes a 20l and over gasoline engine today I never heard of it.

    If one actually needs all that power is another thing and they could certainly go for turbines to get it, but fact is turbine boats are rare and big horses are either diesel or a collection of outboards.
    Fashion then follows and we have people with 4x100HP outboards on the transom.
     
    cracked_ribs likes this.
  2. Ike
    Joined: Apr 2006
    Posts: 2,363
    Likes: 249, Points: 63, Legacy Rep: 1669
    Location: Washington

    Ike Senior Member

    The other forum I referenced talks a lot about this, and you are right. The big issue is speed but at the same time they carp about people who go too fast. Yes, they also talk about 40 foot and up center consoles doing 50-60 mph. That's nuts. I've gone that fast in smaller boats on fairly calm waters and it's still pretty scary. I can't imagine doing that on the ocean except on an exceptionally calm day. I've seen what happens to these offshore racers when pushed to the limits. And can you imagine how much those outboards cost? It;s got to be far more than the boat costs.
     
  3. DCockey
    Joined: Oct 2009
    Posts: 4,622
    Likes: 281, Points: 83, Legacy Rep: 1485
    Location: Midcoast Maine

    DCockey Senior Member

    There is a difference between someone wanting a boat which will go 60 knots and actually going 60 knots, assuming they ever go 60 knots more than once or twice during the time they own the boat, and then only in ideal conditions.
    Multiple high power outboards are expensive and the price can be in the luxury car/truck range, but some of the large outboard boats cost more than typical houses in many parts of the US. It's an entirely different world than buying a fishing boat at Bass Pro Shops.
     
    Last edited: Mar 21, 2020
  4. DCockey
    Joined: Oct 2009
    Posts: 4,622
    Likes: 281, Points: 83, Legacy Rep: 1485
    Location: Midcoast Maine

    DCockey Senior Member

    Mercury Racing offers a gasoline engine for marine use rated at 1350 HP. It's intended for performance boat use so presumably it is intended to be run continuously at full throttle, but probably would require refresh/overhauling/rebuilding at many fewer hours than lower power gasoline engines. It is interesting that the webpage for the engine lists a factory refresh program.
    https://www.mercuryracing.com/wp-content/uploads/2019/12/4285_1350-1100_Race_ss_Final-compressed.pdf
    1350 https://www.mercuryracing.com/sterndrives/engines/1350-2/
     
    Rumars likes this.
  5. Ike
    Joined: Apr 2006
    Posts: 2,363
    Likes: 249, Points: 63, Legacy Rep: 1669
    Location: Washington

    Ike Senior Member

    No argument there. It's called bragging rights. Like having a car that will go 150 mph, but nowhere allows it to be driven at that speed (at least not on US roads).
     
  6. Mr Efficiency
    Joined: Oct 2010
    Posts: 8,549
    Likes: 500, Points: 83, Legacy Rep: 702
    Location: Australia

    Mr Efficiency Senior Member

    Just about nowhere in the world, except on a race track. Until comparatively recently in the Northern Territory of Australia, there was no ceiling, and people were taking high performance cars there solely to exploit the opportunity. Vehicles were clocked as high as 200 miles per hour in some cases, on long straight stretches. At that speed, a kangaroo struck would likely kill everyone aboard.
     
  7. Mr Efficiency
    Joined: Oct 2010
    Posts: 8,549
    Likes: 500, Points: 83, Legacy Rep: 702
    Location: Australia

    Mr Efficiency Senior Member

    At a certain size, a big turbo-diesel driving a surface chopping prop, or jet drive, would give similar performance to a bunch of outboards. How practical is another matter. But the crowd couldn't see what you had hidden under the bonnet. :)
     
  8. Mr Efficiency
    Joined: Oct 2010
    Posts: 8,549
    Likes: 500, Points: 83, Legacy Rep: 702
    Location: Australia

    Mr Efficiency Senior Member

    I know whenever I hooked onto a decent fish, first job was get the outboard leg(s) out of the water, to avoid fouling the line, having to raise five engines, well the fish has probably gotten away by then.
     
  9. Rumars
    Joined: Mar 2013
    Posts: 643
    Likes: 242, Points: 43, Legacy Rep: 39
    Location: Germany

    Rumars Senior Member

    Thank you for that. I am not in the high power scene and was not aware of it. I looked a bit but could not find reliable info about TBO at full power. Found some talk about 120-200h for recreational and 25h for racing use but nothing "official". Price with transmission is in the 200 000 range.

    Now if someone can point me towards a turbine outboard...
     
  10. Mr Efficiency
    Joined: Oct 2010
    Posts: 8,549
    Likes: 500, Points: 83, Legacy Rep: 702
    Location: Australia

    Mr Efficiency Senior Member

    A big, single turbo diesel driving a jet sounds like a better idea, but of course the hull has to be right, and a lot are not really suitable, especially if they are relying on the drive legs to supply some portion of the broach resistance.
     
    bajansailor likes this.
  11. brendan gardam
    Joined: Feb 2020
    Posts: 158
    Likes: 10, Points: 18
    Location: east gippsland australia

    brendan gardam Senior Member

    . nice little tender for your big boat.
     
  12. brendan gardam
    Joined: Feb 2020
    Posts: 158
    Likes: 10, Points: 18
    Location: east gippsland australia

    brendan gardam Senior Member

    i read once that the origonal yamaha 350 v8 outboard was designed for boat manufacturers to do away with large petrol inboards. inboards are fitted in the early stages of construction requiring the factory to carry the cost of the driveline for weeks where an outboard can be fitted after the boat is complete or even when the boat is sold.
     
  13. bajansailor
    Joined: Oct 2007
    Posts: 990
    Likes: 261, Points: 63, Legacy Rep: 37
    Location: Barbados

    bajansailor Marine Surveyor

    How about Mary Slim?
    A 'VSV' (very slender vessel) with a 1,650 hp V12 Caterpillar C32 driving a Rolls Royce water jet.
    VSV Mary Slim - The Multihull Centre https://www.multihullcentre.com/multimarine/past-projects/vsv-mary-slim/

    I think that she would be a lot more fun (and have more sex appeal) than a multiple outboard centre console?

    Mary Slim.jpg

    Safehaven Marine in Ireland also build similar vessels in the form of the XSV 17 and the XSV 20.
    https://www.safehavenmarine.com/xsv-17

    https://www.safehavenmarine.com/xsv20
     
    Last edited: May 14, 2020
  14. Mr Efficiency
    Joined: Oct 2010
    Posts: 8,549
    Likes: 500, Points: 83, Legacy Rep: 702
    Location: Australia

    Mr Efficiency Senior Member

    It reminded me of the movie Das Boat, just that little bit, I wonder what might happen in a big following sea. at speed.
     

  15. bajansailor
    Joined: Oct 2007
    Posts: 990
    Likes: 261, Points: 63, Legacy Rep: 37
    Location: Barbados

    bajansailor Marine Surveyor

    I am guessing that the rationale behind her is that even if they stuff the bow deeply into the wave ahead while surfing in a big following sea, she just keeps going (hopefully not too much like a submarine) as her bow is so slim.
    It certainly would not be much fun if she then decided to broach around instead!
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.